Motor vehicle braking device



Nov. 14, 1933. F. c. RABER LLOTOR VEHICLE BRAKING DEVICE Filed March 25, 1931 2 Sheets-Sheet 1 ENVENTOR Raw/mm! :5". 595m ATTO RNEY:

F. c. RABER 1,935,414

Nov. 14, 1933.

MOTOR VEHICLE BRAKING DEVICE Filed March 23, 1931 2 Sheets-Sheet 2 I El/2 I NVENTO R fkmv/rulv 0. 199.95

ATTORNEYS Pateined Nov. 14, 1933 '1 935- 114 UlTED-STATES PATENT? OFFICE MOTOR VEHICLE BRAKING DEVICE Franklin 0. Babel, Akron, Ohio Application March 23, 1931: Serial No. 524,504 11 Claims. (Cl. 1912-4) This invention relates to braking devices for within the housing 22, is a ratchet 26 that has use on motor propelled vehicles, and more espean axially extending hub portion 27 of reduced cially it relates to devices which automatically diameter, although the' member 27 may be a prevent retrograde movement of the vehicle when separate piece if desired. The cover plates 23,

5 the driving means thereof is inoperative, either 24 are formed with respectivev axial bosses 23, 60

because the clutch is disengaged or the gear- 24 in which are mounted thrust bearings 28, 28 shift lever is in neutral position, and yet permit which constitute additional supports for the shaft the vehicle to be driven backward by means of 15, and also serve as a means for centering the its reverse gear. I ratchet laterally of the housing. Nuts or glands 1c The. chief objects of the invention are auto- 29, 29 are threaded into the respective axial bosses 65 matically and positively to prevent backward 23 24 for retaining the bearings 28 therein, movement of the vehicle except when reversely and, each of aid t 1 provided with an driven by the engine; to provide a simple and 1 nular packing 30 that embraces the shaft to effective device for accomplishing the foregoing prevent the escape of lubricant from the braking 15 object; and to provide for quietness of operadevice. The housing is provided with a grease- 70 tion in such a device. A further object is to gun connection 31 through which lubricant may avoid the dangerous situations present when an be forced into its interior. automobile stalls or is pa d on an upgrade. A pawl 32 is pivotally mounted within the hous- Of the accompanying drawings: ing 22' at the top thereof, upon a rod 33 that is Fi ur 1 i a plan view ofthe chassis of an supported at its ends by the respective cover 75 automobile, and the imDIOVBd braking device, plates 23, 24. The pawl 32 is adapted to engage its preferred form, associated with the drive shaft th t eth of th ratchet 26, the arrangement being thereof; e such that when the pawl and ratchet are engaged Figure 2 iS a Vertical seetion through the brakretrogressive movement of the vehicle is preventing device taken on the line of Figure ed. Preferably the housing structure fits close? 80 Fi u 3 is a s t on the lin 3-3 of Figure 1y against the pivoted end of the pawl so that the 2; and rod 33 is relieved of strain incidental to brak- .Fi u 4 i a section on the line of ing. A torsion spring 34 is mounted upon the me rod 33 and has its respective ends engaging the In general the invention comprises ratchet and pawl and t e front cover plate, the spring being 35 pawl mechanism associated with the drive shaft so r g d as yieldingly to urge the pawl lightly of an automobile, and so constructed and artoward mtchet engeging position ranged that the pawl automatically is engaged pi t l attached at 35 to side f the new or disengaged from the ratchet according to the 2 a depending link 36 that has opposite end 35 direction of rotation of the drive shaft, includforked and has a roller 37 jonrnaled in said f rk no ing means for disengaging the pawl from the \said link being so positioned that the roller 37 ratchet when the gear-shift lever is in reverse rests againstme hub portion 27 of the ratchet hihg Position 26. The roller 37 is normally urged against the Referring to Figure 1 of the drawings 10 is hub 27 by an arcuate plate 38 thatis pivotally 40 the frame of a motor vehicle of the passenger mounted at its upper end in a boss or ear 39 that 95 type, 11 is the motor engine thereof, 13 is is formed on the inner periphery of the housing the transmission housing, 14 iS the gear-shift 22 radially of t hub 27 h lower end lever 15 is the drive Shaft 16 is the umversal tion of the plate 38; below the roller 37, is aperjomt' is the rear axle assembly a 18 tured at 40, and a stud 41 extends through said 45 are the respective wheels of the The aperture and has a threaded portion that extends 10o improved braking device, generally designated through the Wall of the housing 22 so as 0 is mounted upon a sunfab-le trainsyerse Supmit the stud to be rotated from outside the housport 21 between the transmission housing 13 and ing to effect axial adjustment of the Stud. A the universal joint 16, the drive shaft 15 excompression spring 42 is mounted upon thestud 5o tending through the device. 105

41 between the housmg wall and the plate 38 so The braking device 20 comprises an annular housing 22 that is bolted to the support 21 and' as normally to urge the letter, against the roller 37, and the inner end of thestud 41 has an encover plates 23, 24 that are secured respectively to the front and rear of the housing by bolts larged head or'flange 41 to limit the movement 25 r the like. Keyed to the drive shaft 15, of the plate 38 under the impetus of the spring 42, upon occasion, as when the apparatus is being assembled or taken apart.

In order that the pawl 32 may be removed automatically from engagement with the ratchet 26 when the vehicle is reversely driven by the engine, a link 44 is pivotally connected to the free end portion of the pawl 32 and extends upwardly through the wall of the housing 22 at the top thereof, said link being slidable in the housing wall. The slideway of the link 44 transects a rectangular aperture or slideway 45 formed in the housing 22 and cover plates 23, 24, said slide-.

way extending through the device from front to rear. A bracket 46 mounted upon the front cover plate 23 has formed therein a continuation of the slideway 45 that is circular in section to receive a cylindrical cam rod 47, the rear end of which is rectangular in section to lit the slideway 45.

The rear end of the cam rod 47 is beveled or tapered at 48 to constitute a cam, the end of which extends into a longitudinal slot 49 formed in the link 44 and engages a cam roller 50 journaled therein.

The cam rod 4'? normally is urged toward the front, in which position the cam 48 is substantially withdrawn from the slot 49; by means of a compression spring 51 that is mounted upon the cam rod between a collar 52 thereon and the front end of the bracket 46. The front end of the cam rod is angularly bent to provide an offset portion 53 that is positioned adjacent the transmis- ,sion housing 13 in front of the end of reverse rection with the result that the pawl 32 is lifted by the teeth of the ratchet, and then raised above said teeth by the. action of the hub member 27 upon the roller 3'7 which results in the lifting of the link 36 upwardly as is shown in broken lines in Figure 2. The respective members retain the positions described when the vehicle is moving forward or is stationary, the spring-pressed plate 38 holding the roller 37 against retrogressive movement when'the car is stationary. If, however, the vehicle starts to drift or move backward,

the counter-clockwise movement of the ratchet hub 27 against the roller 37 causes the link 36 to be drawn downwardly whereby the free end of the pawl 32 is brought into the path of the ratchet teeth and engaged thereby as is shown in. full lines in Figure 2. The torsion spring 34 raising or lowering the pawl, power is imparted to the link 36 by reason of the differential friction on the opposite sides of the roller 37, that is, there is sliding friction between the roller 37 and the plate 38 whereas the friction between the roller and the hub 27 is rolling friction. Thus the roller moves longitudinally of the plate 38 when rotated by the hub 2'7.

When the vehicle is to be reversely driven by the engine, the moving of the gear-shift lever 14 into reverse position causes the rod 54 to be moved rearwardly to the position shown in broken lines in Figure 3, with the result that the cam rod 47 is moved rearwardly against the pressure of the spring 51, and the cam face 47, by moving under the roller 50 as shown, either lifts the link 44 or secures it in lifted position whereby the pawl 32 positively is held out of engagement with the ratchet 26.

The device is positive and automatic in its action. It is simple in construction and easily may be designed to fit any make of vehicle. Also the device is noiseless in operation since the pawl is positively held out of engagement with the ratchet except at such times as the vehicle is moving backward and not in reverse gear.

The device may be variously modified within the scope of the appended claims which are not limited wholly to the specific construction shown and described. 3,

What is claimed is:

1. In a motor vehicle braking device, the combination of a drive shaft for driving the vehicle in two directions, a ratchet mounted on said drive shaft, a pawl associated with said ratchet mounted upon a stationary member, an operating link pivotally connected to said pawl, a roller journaled in the free end of said link, and means for applying differential friction to opposite sides of said roller to cause longitudinal movement of the link for moving the pawl into orout of engagement with the ratchet.

2. A combination as defined in claim 1 in which rolling friction is applied to one side of the pawllink roller and sliding friction to its other side.

3. In a device of the character described, the combination of a drive shaft for driving a vehicle in two directions, a ratchet mounted on said drive shaft, a pawl associated with said ratchet, an operating link connected at one end to said pawl, a roller journaled inthe opposite end of said link, a rotary member associated with the drive shaft, and a member frictionally engaging said roller and urging it against said rotary member.

4. A combination as defined in claim 3 in which the member that frictionally engages the roller is a pivotally mounted plate, including yielding means for urging the plate against the roller.

5. In a device of the character described, the combination of a drive shaft for'driving a vehicle in two directions, a ratchet mounted upon said drive shaft, a pawl associated with said ratchet, a link connected to said pawl, means for effecting longitudinal movement of said link to engage or disengage the pawl from the ratchet, a second link connected to the pawl, and means for longitudinally moving the .second link automatically to disengage the pawl from the ratchet when the vehicle is placed in reverse gear.

6. A combination as defined in claim 5 in which the means for moving the second link comprises a cam.

7. A combination as defined in claim 5 in which the means for reciprocating the first mentioned link operates through friction therewith.

8. In a device of the character described, the combination of a drive shaft for driving a vehicle in two directions, a ratchet mounted upon said drive shaft, a pawl associated with said ratchet, a link connected to said pawl, means controlled by movement of the drive shaft for effecting longitudinal movement of said link to engage or disengage the pawl from the ratchet, a second link connected to the pawl, and means for ,moving the second link to disengage the pawl from means, a device arranged to move into and out of operative relation with said toothed member, to

prevent its rotation in one direction, an operating link pivotally connected to said device, a roller journaled in the free end of said link, and means for moving the roller over a stationary surface to efi'ect operative movement of said link.

10. In a device of the character described, the combination of a drive shaft for driving a vehicle in two directions, a toothed member on said drive shaft, a member arranged to move into and out of operative relation with said toothed member, to prevent its rotation in one direction, an operating link connected to said last mentioned member, a roller journaled in the free end of said link, and means controlled by movement of the driven shaft for applying difierential friction to opposite sides of said roller to efiect operative movement of said link.

11. In a device of the character described, a rotatable shaft, a ratchet on said shaft, a pawl associated with saidratchet, yielding means normally urging the pawl toward the ratchet, a link pivotally connected to said pawl for moving it out of engagement with said ratchet, a roller journaled in the free end of said link, and means for driving the roller, against a stationary surface, to effect longitudinal movement of said link.

' FRANKLIN c. RABER. 

